The terrain of the moon is a crater. Autumn is the best season to observe constellations. The change of the moon phase is regular. The moon is a very round sphere.

The terrain of the moon is a crater. Wrong (the statement is inexplicable, just like the earth's landform is a basin, and the basin is the earth's landform, but the earth's landform is not just a basin).

Autumn is the best season to observe constellations. Wrong (the statement is still puzzling, just like spring is the best season for the stock market, and two things are not directly related)

The change of the moon phase is regular. correct

The moon is a very round sphere. Error (surface potholes)

The obvious sign of Ursa major is the Big Dipper. Correct (adding words at most is also reasonable)